HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Gjettermann, B. Articles by Hansen, H. C. B. Search for Related Content PubMed PubMed Citation Articles by Gjettermann, B. Articles by Hansen, H. C. B. Agricola Articles by Gjettermann, B. Articles by Hansen, H. C. B. Related Collections Phosphorus Soil Chemistry

TECHNICAL REPORTS

Vadose Zone Processes and Chemical Transport

Sorption and Fractionation of Dissolved Organic Matter and Associated Phosphorus in Agricultural Soil

^a DHI–Water and Environment, Dep. of Hydrology, Soil and Waste, Agern Allé 11, DK-2970 Hørsholm, Denmark
^b The Univ. of Copenhagen, Faculty of Life Sciences, Højbakkegård Allé 9, DK-2630 Taastrup, Denmark
^c The Univ. of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark

^* Corresponding author (bgj{at}life.ku.dk)

Received for publication February 24, 2006. Mobility of dissolved organic matter (DOM) strongly affects the export of nitrogen (N) and phosphorus (P) from soils to surface waters. To study the sorption and mobility of dissolved organic C and P (DOC, DOP) in soil, the pH-dependent sorption of DOM to samples from Ap, EB, and Bt horizons from a Danish agricultural Humic Hapludult was investigated and a kinetic model applicable in field-scale models tested. Sorption experiments of 1 to 72 h duration were conducted at two pH levels (pH 5.0 and 7.0) and six initial DOC concentrations (0–4.7 mmol L^–1). Most sorption/desorption occurred during the first few hours. Dissolved organic carbon and DOP sorption decreased strongly with increased pH and desorption dominated at pH 7, especially for DOC. Due to fractionation during DOM sorption/desorption at DOC concentrations up to 2 mmol L^–1, the solution fraction of DOM was enriched in P indicating preferred leaching of DOP. The kinetics of sorption was expressed as a function of how far the solution DOC or DOP concentrations deviate from "equilibrium." The model was able to simulate the kinetics of DOC and DOP sorption/desorption at all concentrations investigated and at both pH levels making it useful for incorporation in field-scale models for quantifying DOC and DOP dynamics.

Abbreviations: DIP, dissolved inorganic phosphorus • DOC, dissolved organic carbon • DOM, dissolved organic matter • DON, dissolved organic nitrogen • DOP, dissolved organic phosphorus